KR20140107936A - Luminance adjusting part, display apparatus having the same and method of adjusting luminance using the same - Google Patents

Abstract

A luminance adjustment part includes a luminance determination part and a data compensation part. The luminance determination part may determine the luminance of a backlight assembly using de-gamma image data which is generated by performing a de-gamma process on input image data. The compensation part may compensate pixel data of a display panel using the input image data and the luminance of the backlight assembly. Thus, color distortion of a displayed image as perceived by a viewer may be minimized when power consumption of a display apparatus is decreased.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a luminance adjusting unit, a display device including the same, and a luminance adjusting method using the same. [0002]

The present invention relates to a brightness adjusting unit, a display device including the brightness adjusting unit, and a brightness adjusting method using the brightness adjusting unit. More particularly, the present invention relates to a brightness adjusting unit for reducing power consumption and minimizing color distortion, ≪ / RTI >

Generally, a liquid crystal display device includes a liquid crystal display panel that displays an image using light transmittance of a liquid crystal and a light source module that supplies light to the liquid crystal display panel. For example, the light source module may be a backlight assembly.

The liquid crystal display panel includes a first substrate having a pixel electrode and a thin film transistor electrically connected to the pixel electrode, a second substrate having a common electrode and color filters, and a liquid crystal layer interposed between the first substrate and the second substrate. Layer. Alternatively, the liquid crystal display includes a first substrate including a pixel electrode and a common electrode, a second substrate facing the first substrate, and a liquid crystal layer interposed between the substrates. A voltage is applied to the two electrodes to generate an electric field in the liquid crystal layer, and the intensity of the electric field is adjusted to adjust the transmittance of light passing through the liquid crystal layer to obtain a desired image.

The light source module includes light sources for generating light necessary for displaying an image on the liquid crystal display panel. For example, the light sources include a cold cathode fluorescent lamp (CCFL), an external electrode fluorescent lamp (EEFL), a flat fluorescent lamp (FFL), a light emitting diode , LED).

The luminance of the light source module can be adjusted according to the image data displayed by the display panel in order to reduce the power consumption of the display device. For example, when a relatively dark image is displayed, the brightness of the light source module can be reduced. At this time, the gray-scale data of the image displayed on the display panel may be increased in correspondence with the brightness of the reduced light source module to compensate the image data.

Conventionally, a maximum value among the R, G, and B data of each pixel is extracted and used to adjust the luminance of the light source module. However, since the maximum value among the R, G, and B data does not reflect the perceived brightness of a person, the brightness of the display image is distorted.

In addition, when the image data is compensated using the distorted luminance, color, saturation and luminance of the display image are further distorted.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a luminance adjusting unit capable of reducing power consumption and minimizing color distortion.

Another object of the present invention is to provide a display device including the brightness controller.

It is still another object of the present invention to provide a luminance adjusting method using the luminance adjusting unit.

According to an aspect of the present invention, a luminance adjusting unit includes a luminance determining unit and a data compensating unit. The brightness determining unit determines the brightness of the backlight assembly using the de-gamma image data obtained by de-gamma processing the input image data. The data compensator compensates the pixel data of the display panel using the luminance of the input image data and the backlight assembly.

In one embodiment of the present invention, the brightness determining unit may determine the brightness of the backlight assembly using the linear brightness value of the input image data. The data compensator may compensate the pixel data of the display panel using the nonlinear luminance value of the input image data.

In one embodiment of the present invention, the brightness determining unit may determine the brightness of the backlight assembly during the second frame using the average brightness value and the maximum brightness value of the linear brightness value corresponding to the first frame.

In one embodiment of the present invention, the brightness determining unit may include a low-pass filter that does not abruptly change the brightness of the backlight assembly according to a frame.

In one embodiment of the present invention, the brightness controller may further include a degamma unit, a brightness extractor, an average brightness determiner, and a maximum brightness determiner. The degamma unit may receive the input image data and generate the degamma image data. The luminance extraction unit may extract the linear luminance value based on the degamma image data. The average luminance determining unit may determine an average luminance value of the frame based on the linear luminance value. The maximum luminance determination unit may determine the maximum luminance value of the frame based on the linear luminance value.

In one embodiment of the present invention, the degamma image data may have RGB color coordinates. The linear luminance value may be determined by a sum of 20% of the degamma red data, 70% of the degamma green data, and 10% of the degamma blue data.

In one embodiment of the present invention, the input image data may have RGB color coordinates. The luminance controller may further include a first conversion unit for receiving the input image data and converting the input image data into YCbCr color coordinates, and a second conversion unit for receiving compensation data having the YCbCr color coordinates from the data compensation unit and converting the compensation data to RGB color coordinates .

일 수 있다. In one embodiment of the present invention, the data compensator may compensate the pixel data by multiplying the luminance component of the pixel data by the luminance compensation ratio. When the luminance compensation ratio is LCR and the duty ratio of the backlight assembly is DC,

Lt; / RTI >

이고, 상기 백라이트 어셈블리의 상기 듀티비가 50%보다 크면

일 수 있다. In one embodiment of the present invention, the data compensator may compensate the pixel data by multiplying the luminance component of the pixel data by the luminance compensation ratio. If the duty ratio of the backlight assembly is 25% to 50% when the luminance compensation ratio is LCR and the duty ratio of the backlight assembly is DC

, And if the duty ratio of the backlight assembly is greater than 50%

Lt; / RTI >

In one embodiment of the present invention, the data compensator may include a luminance compensator that multiplies the luminance component of the pixel data by a luminance compensation ratio, and a luminance compensator that multiplies the luminance compensation factor by the luminance compensation factor, And a color accumulation compensating unit for performing color accumulation compensation when the color accumulation compensation unit performs the color accumulation compensation.

일 수 있다.In one embodiment of the present invention, a boundary value of a color region is set in consideration of a color space of the pixel data and a duty ratio of the backlight assembly, a boundary value of the color region is multiplied by a constant, The input luminance value obtained by multiplying the luminance component of the pixel data by the luminance compensation ratio is Yin, the output luminance value of the color cluster compensation section is Yout, the boundary value of the color region is C1, the threshold value is C2 When the value obtained by multiplying the boundary value of the gamut by the luminance compensation ratio is C3,

Lt; / RTI >

According to another aspect of the present invention, a display device includes a display panel, a backlight assembly, a gate driver, a data driver, a backlight driver, and a timing controller. The display panel displays an image. The backlight assembly provides light to the display panel. The gate driver provides a gate signal to the display panel. The data driver provides a data voltage to the display panel. The backlight driver provides a backlight driving signal to the backlight assembly. Wherein the timing controller comprises: a brightness determination unit for determining a brightness of the backlight assembly using a degamma image data obtained by de-gamma processing of input image data; a brightness determination unit for determining brightness of the backlight assembly using the brightness of the input image data and the backlight assembly; And a data compensator for compensating pixel data of the display panel. The timing controller controls the gate driver, the data driver, and the backlight driver.

According to another aspect of the present invention, there is provided a brightness adjusting method comprising: degamma-processing input image data to generate degamma image data; calculating a luminance of the backlight assembly using the degamma image data; And compensating pixel data of the display panel using the brightness of the input image data and the backlight assembly.

In one embodiment of the present invention, the step of determining the luminance of the backlight assembly uses a linear luminance value of the input image data. The step of compensating the pixel data uses a nonlinear luminance value of the input image data.

In one embodiment of the present invention, the determining of the brightness of the backlight assembly may include calculating a brightness of the backlight assembly during a second frame using an average brightness value and a maximum brightness value of the linear brightness value corresponding to the first frame, You can decide.

In one embodiment of the present invention, the step of determining the brightness of the backlight assembly may include a step of low-pass filtering such that the brightness of the backlight assembly does not change abruptly according to the frame.

In one embodiment of the present invention, the step of determining the luminance of the backlight assembly includes the steps of extracting the linear luminance value based on the degamma image data, determining an average luminance value of the frame based on the linear luminance value, And determining a maximum luminance value of the frame based on the linear luminance value.

In one embodiment of the present invention, the degamma image data may have RGB color coordinates. The step of extracting the linear brightness value may comprise summing 20% of the degamma red data, 70% of the degamma green data, and 10% of the degamma blue data.

In one embodiment of the present invention, the input image data may have RGB color coordinates. Wherein the compensation of the pixel data comprises receiving the input image data and converting the input image data into YCbCr color coordinates, compensating the pixel data having the YCbCr color coordinates, and compensating the compensated pixel data having the YCbCr color coordinates Into RGB color coordinates.

In one embodiment of the present invention, the step of compensating for the pixel data includes multiplying a luminance component of the pixel data by a luminance compensation ratio, and a step of multiplying a luminance component of the pixel data by the luminance compensation ratio, , Color compensation may be performed.

According to the brightness controller, the display including the brightness controller, and the brightness controller using the brightness controller, the brightness of the backlight assembly can be adjusted according to the image data to reduce the power consumption of the display device.

In addition, when the brightness of the backlight assembly is adjusted, the color distortion of the display image can be minimized because it reflects the perceived brightness of a person.

1 is a block diagram showing a display device according to an embodiment of the present invention.
2 is a detailed block diagram showing the display device of Fig.
3 is a block diagram showing the timing controller of Fig.
FIG. 4 is a block diagram showing the brightness controller of FIG. 3. FIG.
5A is a graph showing a luminance curve of input image data.
5B is a graph showing the luminance curve of the degamma image data passed through the degamma part.
FIG. 6 is a block diagram showing the data compensator of FIG. 4;
7 is a graph showing the operation of the color cluster compensation unit of FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in more detail with reference to the accompanying drawings.

1 is a block diagram showing a display device according to an embodiment of the present invention. 2 is a detailed block diagram showing the display device of Fig.

1 and 2, the display apparatus includes a display panel 100, a backlight assembly 200, a timing controller 300, a display panel driver 400, and a backlight driver 500. The display panel driver 400 includes a gate driver 410, a gamma reference voltage generator 420, and a data driver 430.

The display panel 100 displays an image. The display panel 100 includes a display unit for displaying an image and a peripheral unit disposed adjacent to the display unit.

The display panel 100 includes a plurality of gate lines GL, a plurality of data lines DL and a plurality of unit pixels electrically connected to the gate lines GL and the data lines DL, . The gate lines GL extend in a first direction D1 and the data lines DL extend in a second direction D2 that intersects the first direction D1.

Each unit pixel may include a switching element (not shown), a liquid crystal capacitor (not shown) electrically connected to the switching element, and a storage capacitor (not shown). The unit pixels may be arranged in a matrix form.

The backlight assembly 200 provides light to the display panel 100. For example, the backlight assembly 200 may include a plurality of light emitting diodes.

The backlight assembly 200 may be a direct-type backlight assembly disposed under the display panel 100 and providing light to the display panel 100. The light source unit 200 may be an edge type backlight assembly disposed corresponding to the sides of the display panel 100 and providing light to the display panel 100.

The backlight assembly 200 may be a global dimming structure in which a plurality of light sources are totally controlled. Alternatively, the backlight assembly 200 may include a plurality of light source blocks, and may be a local dimming structure in which the light source blocks are independently driven.

The timing controller 300 receives input image data RGB and an input control signal CONT from an external device (not shown). The input image data may include red image data, green image data, and blue image data. The input control signal CONT may further include a master clock signal and a data enable signal. The input control signal CONT may further include a vertical synchronization signal and a horizontal synchronization signal.

The timing controller 300 generates a first control signal CONT1, a second control signal CONT2 and a third control signal CONT3 based on the input image data RGB and the input control signal CONT, And generates a control signal DC and a data signal DATA.

The timing controller 300 generates the first control signal CONT1 for controlling the operation of the gate driver 410 based on the input control signal CONT and outputs the first control signal CONT1 to the gate driver 410. [ The first control signal CONT1 may include a vertical start signal and a gate clock signal.

The timing controller 300 generates the second control signal CONT2 for controlling the operation of the data driver 430 based on the input control signal CONT and outputs the second control signal CONT2 to the data driver 430. The second control signal CONT2 may include a horizontal start signal and a load signal.

The timing controller 300 generates a data signal DATA based on the input image data RGB. The timing controller 300 outputs the data signal DATA to the data driver 430.

The timing controller 300 generates the third control signal CONT3 for controlling the operation of the gamma reference voltage generator 420 on the basis of the input control signal CONT and outputs the third control signal CONT3 to the gamma reference voltage generator 420.

The timing controller 300 generates the backlight control signal DC for controlling the operation of the backlight driver 500 based on the input image data RGB and outputs the backlight control signal DC to the backlight driver 500. [ The backlight control signal DC may be a duty ratio signal (%) for adjusting the brightness of the light source of the backlight assembly 200.

The timing controller 300 will be described in detail with reference to FIG.

The gate driver 410 generates gate signals for driving the gate lines GL in response to the first control signal CONT1 received from the timing controller 300. [ The gate driver 410 sequentially outputs the gate signals to the gate lines GL.

The gate driver 410 may be directly mounted on the display panel 100 or may be connected to the display panel 100 in the form of a tape carrier package (TCP). Meanwhile, the gate driver 410 may be integrated in the peripheral portion of the display panel 100.

The gamma reference voltage generator 420 generates the gamma reference voltage VGREF in response to the third control signal CONT3 received from the timing controller 300. [ The gamma reference voltage generator 420 provides the gamma reference voltage VGREF to the data driver 430. The gamma reference voltage VGREF has a value corresponding to each data signal DATA.

The gamma reference voltage generator 420 may be disposed in the timing controller 300 or may be disposed in the data driver 430.

The data driver 430 receives the second control signal CONT2 and the data signal DATA from the timing controller 300 and receives the gamma reference voltage VGREF from the gamma reference voltage generator 420. [ . The data driver 430 converts the data signal DATA into an analog data voltage using the gamma reference voltage VGREF. The data driver 430 outputs the data voltage to the data line DL.

The data driver 430 may be directly mounted on the display panel 100 or may be connected to the display panel 100 in the form of a tape carrier package (TCP). Meanwhile, the data driver 430 may be integrated in the peripheral portion of the display panel 100.

The backlight driver 500 receives the backlight control signal DC from the timing controller 300. For example, the backlight control signal DC may indicate the duty ratio (%) of the light source of the backlight assembly 200.

The backlight driver 500 generates a backlight driving signal DB based on the backlight control signal DC. For example, the backlight driver 500 may be a pulse width modulation (PWM) driving circuit.

The backlight driver 500 outputs the backlight driving signal DB to the backlight assembly 200 to drive the backlight assembly 200.

3 is a block diagram showing the timing controller 300 of FIG.

1 to 3, the timing controller 300 includes a luminance controller 310, an image converter 320, and a signal generator 330. This is logically divided for the sake of convenience of explanation, but it is not classified by hardware.

The luminance controller 310 receives the input image data RGB. The brightness controller 310 determines the brightness of the backlight assembly based on the input image data RGB. The brightness controller 310 compensates the pixel data of the display panel 100 based on the brightness of the input image data and the backlight assembly.

The brightness controller 310 outputs a backlight control signal DC indicating the brightness of the backlight assembly to the backlight driver 500. [ The luminance controller 310 outputs the luminance-compensated pixel data (CRGB) to the image converter 320.

The luminance controller 310 will be described in detail with reference to FIGS. 4 to 7. FIG.

The image converter 320 receives luminance compensated pixel data (CRGB) from the luminance controller 310.

The image converter 320 corrects the gradation of the luminance compensated pixel data CRGB and rearranges the luminance compensated pixel data CRGB to match the format of the data driver 430 to obtain the data signal DATA . The data signal DATA may be a digital signal. The image converter 320 outputs the data signal DATA to the data driver 430.

For example, the image converter 320 may include a color characteristic compensator (not shown) and an active capacitance compensator (not shown).

The color characteristic compensator receives the gray level data of the luminance compensated pixel data (CRGB) and performs an Adaptive Color Correction (ACC). The color characteristic compensation unit may compensate the gray-scale data using a gamma curve.

The active capacitance compensation unit performs dynamic capacitance compensation (DCC) for correcting the gray level data of the current frame data using the previous frame data and the current frame data.

The signal generator 330 receives the input control signal CONT. The first control signal CONT1 for controlling the driving timing of the gate driving unit 410 is generated based on the input control signal CONT and the first control signal CONT1 for controlling the driving timing of the data driving unit 430 2 control signal CONT2. The signal generator 330 generates the third control signal CONT3 for adjusting the driving timing of the gamma reference voltage generator 420 based on the input control signal CONT.

The signal generator 330 outputs the first control signal CONT1 to the gate driver 410 and the second control signal CONT2 to the data driver 430, And outputs it to the gamma reference voltage generator 420.

4 is a block diagram showing the brightness controller 310 of FIG. 5A is a graph showing a luminance curve of input image data (RGB). FIG. 5B is a graph showing a luminance curve of the degamma image data DRGB which has passed through the degamma unit 311. FIG. FIG. 6 is a block diagram showing the data compensator 317 of FIG. 7 is a graph showing the operation of the color cluster compensation unit 317b of FIG.

1 to 7, the luminance controller 310 includes a degamma unit 311, a luminance extraction unit 312, an average luminance determination unit 313, a maximum luminance determination unit 314, A first conversion unit 315, a first conversion unit 316, a data compensation unit 317, and a second conversion unit 318.

The degamma unit 311 receives the input image data RGB. The input image data RGB may have an RGB color space. The degamma unit 311 performs de-gamma processing on the input image data RGB to generate the degamma image data DRGB. The degamma image data may have the RGB color space. The degamma image data may include degamma red data, degamma green data, and degamma blue data.

As shown in FIG. 5A, since the gamma value is generally applied when the input image data RGB is generated by a photographing device such as a camera, the input image data RGB has a non-linear luminance value. That is, the input image data RGB have non-linearly changing luminance values according to the gradation. For example, the gamma value in FIG. 5A may be 1 / (2.2).

As shown in FIG. 5B, since the input image data RGB is degamma-processed by the degamma unit 311, the degamma image data DRGB has a linear luminance value. That is, the degamma image data (RGB) has a luminance value that changes linearly according to the gradation.

The luminance extracting unit 312 receives the degamma image data DRGB. The luminance extraction unit 312 extracts the linear luminance value LY based on the degamma image data DRGB.

For example, the luminance extraction unit 312 may convert the degamma image data (DRGB) having the RGB color space into a YCbCr color space to extract the linear luminance value (LY).

For example, the linear luminance value LY may be determined as a sum of 20% of the degamma red data, 70% of the degamma green data, and 10% of the degamma blue data.

The average luminance determining unit 313 determines an average luminance value (AY) corresponding to one frame based on the linear luminance value (LY). The average luminance determination unit 313 outputs the average luminance value AY to the luminance determination unit 315. [

The maximum luminance determination unit 314 determines a maximum luminance value MY corresponding to one frame based on the linear luminance value LY. The maximum luminance determination unit 314 outputs the maximum luminance value MY to the luminance determination unit 315. [

The luminance determining unit 315 receives the average luminance value AY from the average luminance determining unit 313. [ The luminance determining unit 315 receives the maximum luminance value MY from the maximum luminance determining unit 314. [

The brightness determining unit 315 may determine the brightness DC of the backlight assembly 200 based on the average brightness value AY and the maximum brightness value MY corresponding to the one frame. The brightness determining unit 315 may determine the brightness (DC) of the backlight assembly 200 between the average brightness value AY and the maximum brightness value MY.

For example, the luminance determining unit 315 determines the luminance of the current frame (second frame) based on the average luminance value AY and the maximum luminance value MY of the previous frame (first frame) 200 can be determined.

Alternatively, the brightness determining unit 315 may determine the brightness (DC) of the backlight assembly 200 of the current frame based on the average brightness value AY and the maximum brightness value MY of the current frame have. At this time, the timing controller 300 further includes a frame memory for storing data of the current frame.

The brightness determining unit 315 may include a low-pass filter that does not abruptly change the brightness of the backlight assembly 200 according to a frame.

For example, the luminance (DC) of the backlight assembly 200 may be expressed by the duty ratio of the light source of the backlight assembly 200.

The brightness determining unit 315 outputs the backlight control signal DC indicating the brightness of the backlight assembly 200 to the backlight driver 500 and the data compensator 317.

The first conversion unit 316 receives the input image data RGB. The first conversion unit 316 converts the input image data RGB to generate first converted data YCbCr.

For example, the input image data (RGB) has an RGB color space. The first conversion unit 316 may be an RGB-YCbCr converter that converts an RGB color space into a YCbCr color space. Accordingly, the first conversion data YCbCr may have a YCbCr color space.

The data compensating unit 317 receives the first transformed data YCbCr having the YCbCr color space from the first transforming unit 316. The data compensator 317 receives the backlight control signal DC indicating the luminance of the backlight assembly 200 from the luminance determiner 315.

The first conversion data YCbCr corresponds to the image data displayed on the pixels of the display panel 100 and is compensated by the data compensator 317 and is hereinafter referred to as pixel data YCbCr.

The data compensator 317 compensates the pixel data YCbCr by multiplying the luminance component Y of the pixel data YCbCr by the luminance compensation ratio. The data compensator 317 retains the chrominance components Cb and Cr of the pixel data YCbCr as they are.

The data compensator 317 compensates the pixel data YCbCr to generate compensation data CYCbCr. The compensation data (CYCbCr) also has the YCbCr color space.

At this time, since the first conversion data YCbCr is generated on the basis of the data that has not been subjected to the degamma processing on the input image data RGB, the luminance component Y of the first conversion data YCbCr is non- Value (Nonlinear Y).

As a result, the data compensator 317 uses the luminance DC of the backlight assembly 200 generated by the linear luminance value (Linear Y) as the pixel data (YCbCr) having the nonlinear luminance value (Nonlinear Y) .

In one embodiment of the present invention, when the luminance compensation ratio is LCR and the duty ratio of the backlight assembly 200 is DC, for example, the luminance compensation ratio is determined by the following equation (1).

[Equation 1]

For example, the data compensator 317 may compensate the pixel data YCbCr using a lookup table reflecting the luminance compensation ratio. Therefore, the hardware implementation can be facilitated, and the change of the luminance compensation ratio (LCR) can be made flexible.

In another embodiment of the present invention, when the luminance compensation ratio is LCR and the duty ratio of the backlight assembly 200 is DC, if the duty ratio of the backlight assembly is 25% to 50% 2, and if the duty ratio of the backlight assembly is greater than 50%, the luminance compensation ratio can be determined by Equation (3).

&Quot; (2) "

&Quot; (3) "

The data compensating unit 317 includes a luminance compensating unit 317a for multiplying the luminance component Y of the pixel data YCbCr by the luminance compensation ratio LCR and the pixel data YCbCr, And a color cluster compensation unit 317b that performs color blur compensation when a value obtained by multiplying the luminance component (Y) of the luminance compensation unit by the luminance compensation ratio exceeds a threshold value.

When generating the compensation data CYCbCr by uniformly multiplying the luminance compensation ratio LCR by the luminance component Y of the pixel data YCbCr, the luminance data of a value equal to or greater than a predetermined value of the compensation data CYCbCr are all the maximum luminance Lt; / RTI > Therefore, there is a problem that images having a brightness of a predetermined value or more are all mapped to the same brightness, causing color clustering.

The color cluster compensation unit 317b may set the boundary value C1 of the color region in consideration of the color space of the pixel data YCbCr and the duty ratio DC of the backlight assembly 200. [

First, the raw boundary value C of the color region when the duty ratio DC of the backlight assembly 200 is 100% is calculated. When the pixel data YCbCr is in the Yellow-White-Cyan plane, the raw boundary value C of the color area is determined by the following equation (4), and the pixel data YCbCr is stored in the Cyan- And when the pixel data YCbCr is in the Magenta-White-Yellow plane, it is determined by Equation (6) below.

&Quot; (4) "

C = 0.20 * Cb + 0.45 * Cr + 171.7

&Quot; (5) "

C = -1.84 * Cb + 491

&Quot; (6) "

C = -1.59 * Cr + 459

The boundary value C1 of the color region is expressed by Equation 7 below based on the raw boundary value C of the color region and the duty ratio DC of the backlight assembly 200, Lt; / RTI >

&Quot; (7) "

C1 = C- (1-DC / 100) * 255

The threshold value C2 can be determined by multiplying the boundary value C1 of the gamut by a constant. For example, the constant may be 0.9.

&Quot; (8) "

C2 = Cl * 0.9

A value obtained by multiplying the boundary value (C1) of the color region by the luminance compensation ratio (LCR) can be represented by C3. That is, C3 represents a luminance value at a point where a line indicated by a value obtained by multiplying a luminance component of the pixel data by the luminance compensation ratio meets the boundary value C1 of the color region.

The input luminance value Yin of the color cluster compensation unit 317b may be a value obtained by multiplying the luminance component Y of the pixel data YCbCr by the luminance compensation ratio LCR, The output luminance value Yout is determined by Equation (9).

&Quot; (9) "

Therefore, the luminance (luminance) of the input luminance value Yin generated by multiplying the luminance component Y of the pixel data YCbCr by the luminance compensation ratio LCR to the C3 value exceeding the threshold value C2 The luminance data corresponding to the region R1 is compensated to have a new luminance region R2 connecting the threshold value C2 from the threshold value C1 of the color region.

Accordingly, the color cluster compensator 317b can prevent the images having a predetermined luminance or more from being mapped to the same luminance, thereby improving the display quality.

The second conversion unit 318 receives the compensation data (CYCbCr) having the YCbCr color space.

The second conversion unit 318 converts the compensation data (CYCbCr) having the YCbCr color space into the RGB color space. The second conversion unit 318 outputs the luminance compensation pixel data (CRGB) generated by converting the RGB color space to the image conversion unit 320.

According to the brightness controller of the present invention, the display including the brightness controller, and the brightness controller using the brightness controller, the brightness of the backlight assembly is adjusted using the linear brightness value, and the non- Therefore, even though the brightness of the backlight assembly is adjusted, it is possible to display almost the same color coordinates as in the case where the brightness is not adjusted. Therefore, the color distortion of the display image can be minimized while the power consumption of the display device is reduced.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims. It will be possible.

100: display panel 200: backlight assembly
300: timing controller 310: luminance controller
311: degamma unit 312: luminance extraction unit
313: Average luminance determination unit 314: Maximum luminance determination unit
315: luminance determination unit 316: first conversion unit
317: Data Compensation Unit 318: Second Conversion Unit
400: display panel driver 410: gate driver
420: Data driver 430: Gamma reference voltage generator
500: backlight driver

Claims (20)

A brightness determining unit for determining brightness of the backlight assembly using the de-gamma image data subjected to de-gamma processing of the input image data; And
And a data compensator for compensating pixel data of the display panel using the input image data and the luminance of the backlight assembly. The apparatus of claim 1, wherein the brightness determining unit determines a brightness of the backlight assembly using a linear brightness value of the input image data,
Wherein the data compensator compensates the pixel data of the display panel using the nonlinear luminance value of the input image data. The apparatus of claim 2, wherein the brightness determining unit
Wherein the luminance controller determines the luminance of the backlight assembly during the second frame by using the average luminance value and the maximum luminance value of the linear luminance value corresponding to the first frame. The apparatus of claim 3, wherein the brightness determining unit
And a low-pass filter for preventing the brightness of the backlight assembly from being abruptly changed according to the frame. The apparatus of claim 2, further comprising: a degamma unit receiving the input image data to generate the degamma image data;
A luminance extraction unit for extracting the linear luminance value based on the degamma image data;
An average luminance determiner for determining an average luminance value of the frame based on the linear luminance value; And
And a maximum luminance determination unit for determining a maximum luminance value of the frame based on the linear luminance value. 6. The method of claim 5, wherein the degamma image data has RGB color coordinates,
Wherein the linear brightness value is determined by a sum of 20% of the degamma red data, 70% of the degamma green data, and 10% of the degamma blue data. The apparatus of claim 2, wherein the input image data has RGB color coordinates,
A first conversion unit for receiving the input image data and converting the input image data into YCbCr color coordinates; And
And a second conversion unit for receiving the compensation data having the YCbCr color coordinates from the data compensation unit and converting the compensation data into the RGB color coordinates. The apparatus of claim 2, wherein the data compensator compensates the pixel data by multiplying the luminance component of the pixel data by a luminance compensation ratio,
When the luminance compensation ratio is LCR and the duty ratio of the backlight assembly is DC,

And a brightness adjusting unit. The apparatus of claim 2, wherein the data compensator compensates the pixel data by multiplying the luminance component of the pixel data by a luminance compensation ratio,
If the duty ratio of the backlight assembly is 25% to 50% when the luminance compensation ratio is LCR and the duty ratio of the backlight assembly is DC

, And if the duty ratio of the backlight assembly is greater than 50%

And a brightness adjusting unit. The apparatus of claim 2, wherein the data compensator comprises: a luminance compensator for multiplying luminance components of the pixel data by a luminance compensation ratio; And
And a color cluster compensator configured to perform color cluster compensation when a value obtained by multiplying a luminance component of the pixel data by the luminance compensation ratio exceeds a threshold value. The method of claim 10, further comprising: setting a boundary value of a color region in consideration of a color space of the pixel data and a duty ratio of the backlight assembly,
Determining a threshold value by multiplying a boundary value of the color region by a constant,
An input luminance value obtained by multiplying a luminance component of the pixel data by the luminance compensation ratio is Yin, an output luminance value of the color cluster compensation section is Yout, a boundary value of the color region is C1, a threshold value is C2, When the value obtained by multiplying the boundary value of the luminance compensation ratio by the luminance compensation ratio is C3,

And a brightness adjusting unit. A display panel for displaying an image;
A backlight assembly for providing light to the display panel;
A gate driver for providing a gate signal to the display panel;
A data driver for supplying a data voltage to the display panel;
A backlight driver for providing a backlight driving signal to the backlight assembly; And
A brightness determination unit for determining brightness of the backlight assembly using the degamma image data obtained by performing de-gamma processing on the input image data; a brightness determination unit for determining brightness of the backlight assembly using the brightness of the input image data and the backlight assembly, And a timing controller for controlling the gate driver, the data driver, and the backlight driver, the brightness controller including a data compensator that compensates data. Processing the input image data by a degamma process to generate a degamma image data;
Determining brightness of the backlight assembly using the degamma image data; And
And compensating pixel data of the display panel using the input image data and the brightness of the backlight assembly. 14. The method of claim 13, wherein the step of determining the brightness of the backlight assembly uses a linear brightness value of the input image data,
Wherein the step of compensating the pixel data uses a non-linear luminance value of the input image data. 15. The method of claim 14, wherein determining brightness of the backlight assembly
Wherein the brightness of the backlight assembly is determined during the second frame using an average luminance value and a maximum luminance value of the linear luminance values corresponding to the first frame. 16. The method of claim 15, wherein determining brightness of the backlight assembly
And performing low pass filtering so that the brightness of the backlight assembly does not change abruptly according to the frame. 15. The method of claim 14, wherein determining brightness of the backlight assembly
Extracting the linear luminance value based on the degamma image data;
Determining an average luminance value of the frame based on the linear luminance value; And
And determining a maximum luminance value of the frame based on the linear luminance value. 18. The method of claim 17, wherein the degamma image data has RGB color coordinates,
The step of extracting the linear luminance value
And summing 20% of the degamma red data, 70% of the degamma green data, and 10% of the degamma blue data. 15. The apparatus of claim 14, wherein the input image data has RGB color coordinates,
The step of compensating the pixel data
Receiving the input image data and converting the input image data into YCbCr color coordinates;
Compensating the pixel data having the YCbCr color coordinates; And
And converting the compensated pixel data having the YCbCr color coordinates into the RGB color coordinates. 15. The method of claim 14, wherein compensating the pixel data comprises:
Multiplying a luminance component of the pixel data by a luminance compensation ratio; And
And performing colorimetric compensation when a value obtained by multiplying a luminance component of the pixel data by the luminance compensation ratio exceeds a threshold value.

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